*2.3. Mechanical Properties of the SA–AG-Based Films*

Hydrogel-based films can be prepared from various materials such as proteins, carbohydrates, and lipids that have different mechanical properties. The mechanical properties

of the edible film can be modified by changing the composition of the film or the processing conditions. In the current study, TS and EAB parameters were assessed to evaluate the mechanical properties of the SA–AG composite edible films. The TS of the edible films showed a significant decrease (9.82–3.49 Mpa) when increasing the concentration of the CEO. The minimum TS (3.49 Mpa) was observed in the AC-4 film sample with a maximum concentration (30 µL) of CEO, while the blank AC-1 had the maximum value (9.82 Mpa) (Table 1). Wu et al. [22] showed similar results, where the TS of the gelatin-based films decreased when increasing the concentration of the CEO. The tensile strength can be influenced by several factors such as polymer/plasticizer/other additive type and proportion, as well as their respective interaction with each other.

The results of the EAB of the analyzed SA–AG-based film samples are shown in Table 1. The EAB of the SA–AG-based films significantly increased from 7.57 to 18.41% with the addition of the CEO. The maximum and the minimum EAB values were found in AC-4 and AC-1, respectively. The increase in the EAB of the hydrogel-based films could be due to the addition of the CEO, as the oil acts as a plasticizer and makes films more flexible and less brittle. The results of the present study are in line with Wu et al. [23], who reported an increase in the EAB with the addition of CEO nanoliposomes in the gelatin films. Moreover, different factors affect the EAB of the edible films such as the concentration of the added bioactive compounds, the composition of the film-forming solution, and the conditions and method used for the preparations of films.
